Loopy, Hankel, and Combinatorially Skew-Hankel Tournaments

We investigate tournaments with a specified score vector having additional structure: loopy tournaments in which loops are allowed, Hankel tournaments which are tournaments symmetric about the Hankel diagonal (the anti-diagonal), and combinatorially skew-Hankel tournaments which are skew-symmetric about the Hankel diagonal. In each case, we obtain necessary and sufficient conditions for existence, algorithms for construction, and switches which allow one to move from any tournament of its type to any other, always staying within the defined type

Unicyclic Graphs with equal Laplacian Energy

We introduce a new operation on a class of graphs with the property that the Laplacian eigenvalues of the input and output graphs are related. Based on this operation, we obtain a family of order (square root of n) noncospectral unicyclic graphs on n vertices with the same Laplacian energy.Comment: 11 pages, 11 figures, slightly modified version of Theorem 1 when compared with original pape

Endowments, Fiscal Federalism, and the Cost of Capital for States: Evidence from Brazil, 1891-1930

There is a large literature that aims to explain what determines country risk (defined as the difference between the yield of a sovereign's bonds and the risk free rate). In this paper, we contribute to the discussion by arguing that an important explanatory factor is the impact that commodities have on the capacity to pay. We use a newly created data base with state-level fiscal and risk premium data for Brazil states between 1891 and 1930 to show that Brazilian states with natural endowments that allowed them to export commodities that were in high demand (e.g., rubber and coffee) ended up having higher revenues per capita and, thus, lower cost of capital. We also explain that the variation in revenues per capita was both a product of the variation in natural endowments (i.e., the fact that states cannot produce any commodity they want) and a commodity boom that had asymmetric effects among states. These two effects generated variation in revenues per capita at the state level thanks to the extreme form of fiscal decentralization that the Brazilian government adopted in the Constitution of 1891, which gave states the sole right to tax exports. We end by running instrumental variable estimates using indices of export prices for each state to instrument for revenues per capita. Our IV estimates confirm our results that states with commodities that had higher price increases had lower risk premia.

Computer Aided Business Model Design: Analysis of Key Features Adopted by Users

Business model innovation comprises many theoretical models, frameworks and methodologies; however, there is still little in the way of digital support for them using Computer Aided Design software. In this paper, we present an analysis of real-world usage data from the first generation of such tools that were designed to support the business model canvas. We first present how two artifacts implement features such as colors for grouping, custom attributes and positioning of elements. An examination of how digital support brings about new opportunities in business modeling allows us to compare this with a paper-based version. We then analyze how variations of these features have been used in the real world. Finally, we examine the implications of our observations for the next generation of tools and the advancement of research for dedicated Computer Aided Design tools to support strategic objects such as business models

Bargaining for fiscal control: Tax federalism in Brazil and Mexico, 1870-1940

This paper studies the historical origins of the federalist institutions in Mexico and Brazil. Using a bargaining game model, I argue that the type of commodities each country produced by the end of the nineteenth Century determined the negotiation power of local governments. This led to the buildup of opposite federalist institutions in both countries, which have persisted until nowadays. The model shows that countries with regions with more autonomy to produce and trade their commodities increase the local power to collect more taxes. While in Brazil coffee was the most important commodity, Mexico relied on mining products. Coffee was produced by local landowners who became economically powerful and they were able that export taxes were collected locally with the proclamation of the 1891 Constitution. Empirical estimates show that, after 1891, exporter states increased significantly their own fiscal revenue. On the other hand, mining was capital and technology intensive, inputs that were domestically scarce in Mexico. To finance those activities foreign investment was promoted centrally, weakening the relative power of local elites

An evaluation of the 1997 fiscal decentralization reform in Mexico: The case of the health sector

This paper studies the impact of the health decentralization of funds and responsibilities that took place in Mexico in 1997 on state level health outcomes. It renders two main results. First, the magnitude of transfers from the federal government to states failed to take into account state-specific needs; instead, transfers were mainly determined by the pre-reform health expenditures of the federal government in each state. Second, decentralization did not boost the advances in health outcomes already achieved under the centralized health sector regime. We conclude by discussing plausible reasons for the disappointing impact of decentralization on health outcomes

The feasibility of wireless capsule endoscopy in detecting small intestinal pathology in children under the age of 8 years: a multicentre European study.

Objective: To systematically evaluate the feasibility and methodology to carry out wireless capsule endoscopy (WCE) in children <8 years to define small intestinal pathology. Design: Prospective European multicentre study with negative prior investigation. Patients and interventions: 83 children aged 1.5–7.9 years were recruited. Initially, all were offered “swallowing” (Group 1) for capsule introduction. If this failed endoscopic placement (Group 2) was used and the Roth net, Advance or custom-made introducers were compared. Outcome measures: Primary endpoint: to determine pathology; secondary endpoint: comparison of capsule introduction methods. Results: Capsule introduction: 20 (24%) children aged 4.0–7.9 years (mean, 6.9 years; 14 male) comprising Group 1 were older (p<0.025) than 63 (76%) aged 1.5–7.9 years (mean, 5.25 years; 30 male) forming Group 2. Complications: Roth net mucosal trauma in 50%; no others occurred. The available recording apparatus was inappropriate for those <3 years. Indications: gastrointestinal bleeding: n = 30 (16 positive findings: four ulcerative jejunitis, four polyps, two angiodysplasia, two blue rubber blebs, two Meckel’s diverticula, one anastomotic ulcer, one reduplication); suspected Crohn’s disease: n = 20 (11 had Crohn’s disease); abdominal pain: n = 12 (six positive findings: three Crohn’s disease, two lymphonodular hyperplasia, one blue rubber bleb); protein loss: n = 9 (four lymphangectasia); malabsorption: n = 12 (seven positive findings: six enteropathy, one ascaris). No abnormalities overall: 45%. Conclusion: WCE is feasible and safe down to the age of 1.5 years. 20 children >4 years swallowed the capsule. The Advance introducer proved superior for endoscopic placement. The pathologies encountered showed age specificity and, unlike in adolescents, obscure gastrointestinal bleeding was the commonest indication

Business model design: an evaluation of paper-based and computer-aided canvases

In recent years, Business Model Canvas design has evolved from being a paper-based activity to one that involves the use of dedicated computer-aided business model design tools. We propose a set of guidelines to help design more coherent business models. When combined with functionalities offered by CAD tools, they show great potential to improve business model design as an ongoing activity. However, in order to create complex solutions, it is necessary to compare basic business model design tasks, using a CAD system over its paper-based counterpart. To this end, we carried out an experiment to measure user perceptions of both solutions. Performance was evaluated by applying our guidelines to both solutions and then carrying out a comparison of business model designs. Although CAD did not outperform paper-based design, the results are very encouraging for the future of computer-aided business model design

Visualizing Business Model Evolution with the Business Model Canvas: Concept and Tool

The Business Model Canvas (BMC) assists in the design of companies' business models. As strategies evolve so too does the business model. Unfortunately, each BMC is a standalone representation. Thus, there is a need to be able to describe transformation from one version of a business model to the next as well as to visualize these operations. To address this issue, and to contribute to computer-assisted business model design, we propose a set of design principles for business model evolution. We also demonstrate a tool that can assist in the creation and navigation of business model versions in a visual and user-friendly wa

Chemical ordering and composition fluctuations at the (001) surface of the Fe-Ni Invar alloy

We report on a study of (001) oriented fcc Fe-Ni alloy surfaces which combines first-principles calculations and low-temperature STM experiments. Density functional theory calculations show that Fe-Ni alloy surfaces are buckled with the Fe atoms slightly shifted outwards and the Ni atoms inwards. This is consistent with the observation that the atoms in the surface layer can be chemically distinguished in the STM image: brighter spots (corrugation maxima with increased apparent height) indicate iron atoms, darker ones nickel atoms. This chemical contrast reveals a c2x2 chemical order (50% Fe) with frequent Fe-rich defects on Invar alloy surface. The calculations also indicate that subsurface composition fluctuations may additionally modulate the apparent height of the surface atoms. The STM images show that this effect is pronounced compared to the surfaces of other disordered alloys, which suggests that some chemical order and corresponding concentration fluctuations exist also in the subsurface layers of Invar alloy. In addition, detailed electronic structure calculations allow us to identify the nature of a distinct peak below the Fermi level observed in the tunneling spectra. This peak corresponds to a surface resonance band which is particularly pronounced in iron-rich surface regions and provides a second type of chemical contrast with less spatial resolution but one that is essentially independent of the subsurface composition.Comment: 7 pages, 5 figure